Using Tree Rings to Date Historic Guilford Buildings

Historians rely on documentary evidence and architectural exam to determine the age of historic buildings, but there is a new cutting-edge science that can give the dating process more accuracy.

This emerging science of dendrochronology is being used in Connecticut for dating old buildings, including several in Guilford. Dendrochronology involves tree-ring analysis of oak timber frames, plus microscopic study and computer matching based on a database of over 100 historic structures in Eastern Massachusetts and Connecticut.

On November 2, at the Guilford Keeping Society’s annual meeting, the public will get to hear how Dr. Daniel Miles of the Oxford Dendrochronology Laboratory in Oxfordshore, England used dendrochronology to analyze Guilford's Hyland House ( built 1713) as well as the Comfort Starr House, (built 1695.) This fall, Miles will be sampling timbers at the Keeping Society's own Thomas Griswold House as well as the Pest House in Guilford and the Nehemiah Royce House in Wallingford to determine the year they were built.

The Thomas Griswold House is a classic New England saltbox dwelling standing on a commanding knoll along a picturesque stretch of the old Post Road in Guilford. Thomas Griswold III built the house around 1774, on land that had been in the Griswold family since Thomas Griswold II moved from Wethersfield in 1695. It is on the National Register of Historic Places. The Guilford Keeping Society owns the building and operates it as a museum of early nineteenth-century life.

The other building to be studied is the Town of Guilford's Pest House at Clapboard Hill. Such “pest houses” were constructed during the smallpox epidemic of the late eighteenth century to quarantine those struck with the deadly disease. Minutes of Guilford's town meetings in 1760 show that erection of a Pest House was authorized, but here was a delay in construction. The first reference to its existence is by the year 1775. Dendrochronology may provide additional evidence that a house still standing on Tanner Marsh Road is indeed the Pest House.

A generous grant from the Guilford Preservation Alliance Trust Fund has made it possible to retain the services of Dr. Miles for three of the Guilford houses.

Dr. Miles and his associate in the U.S., Michael Cuba, of Transom Historic Preservation Consulting, are the guest speakers. A short business meeting of the Society will precede the program, which will be held at the Greene Community Center, 32 Church Street, Guilford. The meeting begins at 7 p.m. The public is welcome.